Method for testing oral malodor

ABSTRACT

The present invention relates to a method for testing oral malodor, in particular oral malodor from coffee. Described herein are methods for testing the efficacy of an oral care composition to reduce oral malodor, the method comprising the steps of: a) cleaning at least a part of the oral cavity with an oral care composition; b) testing a sample of exhaled breath from the cleaned oral cavity to provide a test result representing a amount of at least one oral malodor component detected in the exhaled breath; c) exposing the oral cavity to an oral malodor material including or capable of forming the at least one oral malodor component; and d) testing a sample of exhaled breath from the oral cavity to provide a test result representing an amount of the at least one oral malodor component detected in the exhaled breath.

BACKGROUND OF THE INVENTION

Drinking coffee is done worldwide, often providing an energy boost forthe drinker. Coffee drinking is also linked to several health benefitsrelative to non-coffee drinkers, e.g. decrease the chance of developingtype II diabetes, Parkinson's disease, dementia, certain cancers, heartarrythmia and strokes. However, the resultant “coffee breath” resultingfrom coffee drinking is undesirable. This is especially undersirable forthose who drink several cups of coffee throughout the day.

It is known to provide oral care compositions, such as dentifrice,toothpaste, mouthrinse or mouthwash, which have been speciallyformulated to counteract onion or garlic malodor. A large number ofpotential active components or blends are known to be incorporated intooral care compositions for this purpose. Nevertheless, there is still aneed for more effective oral care compositions and active components foreffectively combatting oral malodor from onion or garlic. There iscorrespondingly a need for further research and development to developsuch oral care compositions.

When an oral care composition is being formulated specifically to targetoral malodor from onion or garlic, there is a very wide choice ofpotential active components and component combinations, as well ascomponent amounts. Furthermore, there is often confusion from the useras to whether the malodor reduction is being achieved by odor masking(overwhelming the malodor with another odor) or by elimination orconversion of the malodorous compound into a less malodorous compound,the latter being the preferred means of addressing malodor.

Furthermore, the choice of potential vehicles and other activecomponents for providing efficacy for other technical effects, such asanti-cavity protection, anti-plaque efficacy, and anti-microbialefficacy, is extremely wide.

It is not possible to predict with any degree of certainty how effectiveany particularly formulated oral care composition may be against oralmalodor from coffee. Consequently, each formulation must be individuallytested for efficacy against oral malodor from coffee.

Such testing is time consuming, laborious and costly. Furthermore, it isdifficult to achieve consistent and robust quantitative results whichcan be used as a reliable tool during the research and developmentprocess.

There is a need for a testing method which can efficiently and reliablytest oral care compositions to determine how effective any particularlyformulation may be against oral malodor, for example from coffee.

There is also a need for such a testing method which is less timeconsuming, less laborious and less costly than known testing methods.

Furthermore, there is a need for a testing method which can readilyachieve consistent and robust quantitative results which can be used asa reliable tool during the research and development process for the oralcare composition having the desired efficacy.

SUMMARY OF THE INVENTION

The invention addresses the above needs in the art by providing a methodfor testing the efficacy of and selectin an oral care composition toreduce oral malodor, the method comprising at least one or more of thesteps of:

-   -   cleaning at least a part of the oral cavity with an oral care        composition and testing the cleaned oral cavity to provide a        baseline amount of at least one oral malodor component detected        in the exhaled breath;    -   exposing the oral cavity to an oral malodor material containing        at least one oral malodor component; and    -   obtaining a sample of exhaled breath from the oral cavity to        detect a first amount of the at least one oral malodor component        in the exhaled breath which is a representation of the        propylactic effect of the oral care composition;    -   optionally, comparing the amount of the at least one oral        malodor component detected in the exhaled breath after cleansing        with an oral care composition with an amount from cleansing with        a different oral care composition and selecting the oral care        composition with the lower amount for a method of providing        prophylactic effect against at least one malodor component in        the oral cavity;    -   cleaning at least a part of the oral cavity with the oral care        composition;    -   obtaining a sample of exhaled breath from the oral cavity to        detect an amount of the at least one oral malodor component in        the exhaled breath which is a representation of the efficacy of        the oral care composition to reduce oral malodor;    -   optionally, comparing the amount of the at least one oral        malodor component detected in the exhaled breath after cleansing        with an oral care composition with an amount from cleansing with        a different oral care composition and selecting the oral care        composition with the lower amount for a method of reducing at        least one malodor component in the oral cavity.

As used throughout, ranges are used as shorthand for describing each andevery value that is within the range. Any value within the range can beselected as the terminus of the range.

Further embodiments of the invention will be apparent from the detaileddescription and the examples.

DESCRIPTION OF THE INVENTION

Accordingly, the invention provides a method for testing the efficacy ofand selecting an oral care composition to reduce oral malodor, themethod comprising the steps of:

-   -   a1. cleaning at least a part of the oral cavity with an oral        care composition and testing the cleaned oral cavity to provide        a baseline amount of at least one oral malodor component        detected in the exhaled breath;    -   b1. exposing the oral cavity to an oral malodor material        containing the at least one oral malodor component;    -   c1. obtaining a sample of exhaled breath from the oral cavity to        detect a amount of the at least one oral malodor component in        the exhaled breath which is a representation of the propylactic        effect of the oral care composition; and    -   d1. comparing the amount of the at least one oral malodor        component detected in the exhaled breath after cleansing with an        oral care composition with a amount from cleansing with a        different oral care composition and selecting the oral care        composition with the lower amount for a method of providing        prophylactic effect against at least one malodor component in        the oral cavity.

Another aspect of the invention provides a method for testing theefficacy of and selecting an oral care composition to reduce oralmalodor, wherein the method comprises the steps of:

-   -   e1. exposing the oral cavity to an oral malodor material        containing the at least one oral malodor component;    -   f1. cleaning at least a part of the oral cavity with the oral        care composition;    -   g1. obtaining a sample of exhaled breath from the oral cavity to        detect an amount of the at least one oral malodor component in        the exhaled breath which is a representation of the efficacy of        the oral care composition to reduce oral malodor; and    -   h1. comparing the amount of the at least one oral malodor        component detected in the exhaled breath after cleansing with an        oral care composition in step e1 with a amount from cleansing        with a different oral care composition and selecting the oral        care composition with the lower amount for a method of reducing        at least one malodor component in the oral cavity.

Another aspect of the invention provides a method for testing theefficacy of and selecting an oral care composition to reduce oralmalodor, wherein the method comprises the steps of:

-   -   a2. cleaning at least a part of the oral cavity with an oral        care composition and testing the cleaned oral cavity to provide        a baseline amount of at least one oral malodor component        detected in the exhaled breath;    -   b2. exposing the oral cavity to an oral malodor material        containing the at least one oral malodor component;    -   c2. obtaining a sample of exhaled breath from the oral cavity to        detect a amount of the at least one oral malodor component in        the exhaled breath which is a representation of the propylactic        effect of the oral care composition;    -   d2. optionally, comparing the amount of the at least one oral        malodor component detected in the exhaled breath after cleansing        with an oral care composition with a amount from cleansing with        a different oral care composition and selecting the oral care        composition with the lower amount for a method of providing        prophylactic effect against at least one malodor component in        the oral cavity;    -   e2. cleaning at least a part of the oral cavity with the oral        care composition from step a2;    -   f2. obtaining a sample of exhaled breath from the oral cavity to        detect a amount of the at least one oral malodor component in        the exhaled breath which is a representation of the efficacy of        the oral care composition to reduce oral malodor; and    -   g2. optionally, comparing the amount of the at least one oral        malodor component detected in the exhaled breath after cleansing        with an oral care composition in step e2 with a amount from        cleansing with a different oral care composition and selecting        the oral care composition with the lower amount for a method of        reducing at least one malodor component in the oral cavity.

Another aspect of the invention provides a method for testing theefficacy of and selecting an oral care composition to reduce oralmalodor, wherein the method comprises the steps of:

-   -   a2. cleaning at least a part of the oral cavity with an oral        care composition and testing the cleaned oral cavity to provide        a baseline amount of at least one oral malodor component        detected in the exhaled breath;    -   b2. exposing the oral cavity to an oral malodor material        containing the at least one oral malodor component;    -   c2. obtaining a sample of exhaled breath from the oral cavity to        detect an amount of the at least one oral malodor component in        the exhaled breath which is a representation of the propylactic        effect of the oral care composition;    -   d2. comparing the amount of the at least one oral malodor        component detected in the exhaled breath after cleansing with an        oral care composition with an amount from cleansing with a        different oral care composition and selecting the oral care        composition with the lower amount for a method of providing        prophylactic effect against at least one malodor component in        the oral cavity;    -   e2. cleaning at least a part of the oral cavity with the oral        care composition from step a2;    -   f2. obtaining a sample of exhaled breath from the oral cavity to        detect an amount of the at least one oral malodor component in        the exhaled breath which is a representation of the efficacy of        the oral care composition to reduce oral malodor; and    -   g2. comparing the amount of the at least one oral malodor        component detected in the exhaled breath after cleansing with an        oral care composition in step e2 with a amount from cleansing        with a different oral care composition and selecting the oral        care composition with the lower amount for a method of reducing        at least one malodor component in the oral cavity.

Optionally, the oral malodor material is from coffee.

Optionally, the oral care composition according to the invention is adentifrice, mouthwash, mouthrinse, toothpaste, gel, dental cream,chewing gum, or portable dosage article such as, without limitation, alozenge, a mint, bead, wafer, lollipop, liquid formulated for oralapplication in a small portable nebulizer (spray bottle), liquidformulated for oral application in a small portable drop-generatingbottle, or a soft pliable tablet (“chewie”).

In some embodiments, each cleaning step comprises brushing the teethwith the oral care composition which is a toothpaste or dentifrice gel.

In some alternative embodiments, each cleaning step comprises rinsingthe oral cavity with the oral care composition which is a mouthwash ormouthrinse.

Optionally, the malodor component is a the oral malodor material is aheterocyclic compound. In one embodiment of the invention, theheterocyclic compound is a furan or pyrrole.

Optionally, the malodor component tested is at least one oral malodorcomponent selected from the group consisting of 3-methyl-furan,2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanol acetate,2-methylthio-methylfuran, 1-pentyl-pyrrole, and 2,2′-methylbisfuran.

Further optionally, each testing step tests to detect at least three ofthe oral malodor components selected from the group consisting of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.

Still further optionally, each testing step tests to detect all of theoral malodor components selected from 3-methyl-furan,2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanol acetate,2-methylthio-methylfuran, 1-pentyl-pyrrole, 2,2′-methylbisfuran.

In an embodiment of the invention, the oral care compositions maycomprise one or more of carbonyl compounds such as aldehydes andketones, compounds which encapsulate the furan or pyrrole compounds,tetrasodium pyrophospate, flavorants and combinations thereof.

Optionally, each obtaining step includes the sub-steps of:

-   -   i. collecting the at least one oral malodor component on solid        phase micro extraction (SPME) fibers;    -   ii. separating the collected at least one oral malodor component        using chromatography; and    -   iii. determining an amount of the separated at least one oral        malodor component using mass spectrometry to provide a        quantification representing an amount of the at least one oral        malodor component in the respective sample of exhaled breath.

Optionally, the chromatography is gas phase chromatography (GC) and/orthe mass spectrometry (MS) is triple quadrupole mass spectrometry.

Optionally, step b1 or b2 is carried out from 10 to 30 minutes afterstep a1 or a2, respectively, step c1 or c2 is carried out from 15 to 45minutes after step a1 or a2, respectively, and step e1 or e2 is carriedout from 30 to 60 minutes after step a1 or a2, respectively.

In one embodiment of the invention, the oral care composition selectedin step d1 or d2 is different than the original oral care compositionselected in step a1 or a2.

In one embodiment of the invention, the oral care composition selectedin step g1 or g2 is different than the original oral care compositionselected in step a1 or a2.

Consequently, the preferred embodiments of the invention provide atesting protocol, using associated instruments, to effectively measurecoffee malodor ingredients in the human mouth and to screen the efficacyof oral care compositions with coffee malodor reducing function.

The preferred embodiments of the invention also provide an analyticalmethod to measure coffee malodor in the mouth, in particular theheadspace of the oral cavity, with an in vivo solid phase microextraction (SPME) technique using chromatography, in particular gasphase chromatography, and mass spectrometry, in particular triplequadrupole mass spectrometry.

The preferred embodiments of the method of the invention can effectivelyindicate the concentration level of up to seven coffee odor ingredientsin the human mouth and be used to screen the efficacy of oral careproducts with an coffee malodor reduction function.

The preferred embodiments of the method of the invention can provide anin vivo method capable of differentiation between a control oral carecomposition, such as a toothpaste and a test oral care composition, suchas a toothpaste, specially formulated for the prevention and removal ofcoffee odor from the oral cavity.

In some embodiments, the present invention provides a method for testingthe efficacy of an oral care composition to reduce oral malodor. In thetesting method, the oral malodor is generated by malodor material, forexample being selected from at least one of coffee. Typically, the oralmalodor material comprises a measured dose of the oral malodor material,which is typically in a convenient and reproducible form, such as apowder or extract, although raw or natural material may be employed.

The invention has particular application in the testing for efficacy toreduce coffee malodor. However, the invention may also be used to testfor other oral malodor materials or components.

In one aspect, the method can provide an indication of the ability of anoral care composition prophylactically to reduce oral malodor resultingfrom the oral malodor material.

A freshness test is initially carried out on the cleaned oral cavity, inwhich a sample of exhaled breath is tested for the predetermined oralmalodor component(s) present in the headspace of the cleaned mouth. Thenthe oral cavity is exposed to a dose of the oral malodor material, and afurther sample of exhaled breath is tested for the predetermined oralmalodor component(s) present in the headspace of the odoriferous mouth.

A comparison of the two samples of exhaled breath indicates the abilityof the oral care composition prophylactically to prevent the mouthheadspace from subsequently having malodors resulting from earliercoffee exposure.

First Cleaning of the Mouth Headspace

In a first step, the method cleans at least a part of the oral cavitywith an oral care composition to be tested. The cleaning step typicallycomprises brushing the teeth with the oral care composition, which is atoothpaste or dentifrice gel. Alternatively, the cleaning step maycomprise rinsing the oral cavity with the oral care composition, whichis a mouthwash or mouthrinse. The cleaning step preferably has apredetermined time period, and for example may take from 30 s to 2minutes, typically about 1 minute.

Sampling of the Cleaned Mouth Headspace

The procedures described in this sampling and detection technique forverifying the cleansing of the mouth is also used generally in theinvention for other sampling and detections steps.

A sample of exhaled breath from the cleaned oral cavity is tested todetermine a baseline level of at least one oral malodor componentdetected in the exhaled breath which should be zero or at low levels ofmalodor components.

In this embodiment, the testing step collects the at least one oralmalodor component on solid phase micro extraction (SPME) fibers. Thevolunteer human subject in the testing protocol puts a SPME fiberassembly 2 to their mouth M. The fiber assembly 2 is prevented fromdirect contact with the mouth by a spacer tube 4 of polymeric material.The fiber assembly 2 may typically comprise fused silica fibers having a75 micron coating of Carboxen®/polydimethylsiloxane (CAR/PDMS) as thematrix active group, a suitable fibre assembly 2, having a black plainhub, being available from Supelco, of Bellefonte, Pa., USA. However,other commercially available SPME fibre assemblies may be employed. Thevolunteer human subject breathes in through the nose and out through themouth into the tube 4 and fiber assembly 2.

Then, the oral malodor component(s) collected in the fiber assembly 2are separated using chromatography, typically gas phase chromatography.

For example, in one embodiment, a gas chromatograph (GC) sold under thetrade name GC7890A by Agilent Technologies, Palo Alto, Calif., USA isused. However, other commercially available gas chromatograph equipmentmay be employed.

In one example, in the gas chromatograph the oven temperature is held at35° C. for 1 minute, and then the temperature is increased to 160° C. ata 15° C./min rate and held there for another 2.667 minutes. The totalrunning time may be 12 minutes. Helium may be used as the carrier gasand the flow rate may be 1 mL/min. The injector temperature may be setup at 250° C. A SLBTM-5ms GC column (30 m×0.25 mm×0.25 μm filmthickness, available from Sigma-Aldrich, Bellefonte, Pa.) may be usedfor the separation of the oral malodor component(s) collected in thefiber assembly 2.

After the oral malodor component(s) collected in the fiber assembly 2have been separated, an amount of the separated oral malodorcomponent(s) is determined using mass spectrometry to provide aquantification representing an amount of the at least one oral malodorcomponent in the sample of exhaled breath.

Typically, the mass spectrometer comprises a 7000MS Triple QuadrupoleMass Spectrometer available from Agilent Technologies, Palo Alto,Calif., USA. However, other commercially available mass spectrometerequipment may be employed.

Typical parameter settings on the mass spectrometer are as follows. Thenon-ionization for solvent delay may be from 0 to 0.5 minutes. The massspectrometry detection may be switched on at 0.5 minutes.

The mass spectrometer records a plurality of counts at a respectiveacquisition time for each component detected. The method of theinvention may be used to detect only a single component. However, in thepreferred embodiments, plural components are detected, each having arespective acquisition time, and the counts at each acquisition timerepresents the amount of the respective component present.

In some embodiments, in which the method is for detecting coffeemalodor, the at least one oral malodor component to be detected isselected from at least one of 3-methyl-furan, 2,5-dimethyl-furan,2-furan-methanol, 2-furanmethanol acetate, 2-methylthio-methylfuran,1-pentyl-pyrrole, 2,2′-methylbisfuran. In one embodiment, at least threeof those seven oral malodor components, and in another embodiment sevenoral malodor components are individually detected.

When these particular oral malodor components are detected using the7000MS Triple Quadrupole Mass Spectrometer and the typical parametersettings as set out above, the acquisition times are as follows:

From 0.5 to 2.8 minutes, 2-methyl-furan may be detected with a molecularion at 82.8 and daughter ion at 53.0 and the collision energy was 20 eV.From 2.8 to 4 5 minutes, 2,5-dimethylfuran may be detected with amolecular ion at 96.2 m/z and daughter ion at 81.0 m/z and the collisionenergy was 10 eV. From 4.5 to 5 5 minutes, 2-furanmethanol may bedetected with a molecular ion at 98.2 m/z and daughter ion at 42.1 m/zand the collision energy was 10 eV. From 6.0 to 6.23 minutes,2-furanmethanol acetate may be detected with a molecular ion at 140.2m/z and daughter ion at 98.2 m/z and the collision energy was 10 eV.From 6.23 to 6.70 minutes, 2-methylthio methylfuran may be detected witha molecular ion at 128.2 m/z and daughter ion at 80.9 m/z and thecollision energy was 10 eV. From 6.7 to 7.1 minutes, 1-penyl-pyrrole maybe detected with a molecular ion at 137.2 m/z and daughter ion at 80.9m/z and the collision energy was 10 eV. From 7.1 to 12 0 minutes,2,2′-methyl-bisfuran may be detected with a molecular ion at 148.2 m/zand daughter ion at 91.2 m/z and the collision energy was 10 eV. Thecount total of each component is recorded to indicate the amount of thatcomponent which has been detected. The counts of two or all of thecomponents may be added to provide a unitary parameter representing theoral malodor from the combination of the respective components.

In some embodiments, the testing step further includes the sub-step ofadding together the counts representing the amounts of at least two orall of the detected oral malodor components in the respective sample ofexhaled breath to provide a single quantified total count value for thesample of exhaled breath. The single quantified total count valuerepresents oral malodor associated with the oral malodor material in thecleaned mouth headspace.

Introducing Oral Malodor Material into the Mouth

Thereafter, the oral cavity is exposed to an oral malodor materialincluding or capable of forming the at least one oral malodor component.Typically, the oral malodor material comprises a measured dose.Typically, the exposure to oral malodor material is carried out from 10to 30 minutes, more typically about 20 minutes, after the commencementof the initial cleaning of the oral cavity.

To calibrate the change in odor strength in human mouth after a periodof time, sequentially diluted coffee solutions were used for headspacemethod development and validation with SPME-GC-MRM-MS method. The coffeeconcentrations were from 2 to 16 mg/mL in 37° C. water solution fromwhich range can effectively cover the coffee odor strength in humanmouth.

The average total area under the curve for the coffee malodor materialat the concentration of coffee from 2 mg/mL to 16 mg/mL after threereplications was as follows:

2 mg/mL 120,443 4 mg/mL 295,225 8 mg/mL 783,343 16 mg/mL  1,956,508

The coffee odor may be introduced into the oral cavity by rinsing themouth with 3 mL of that coffee malodor solution for 1 minute.

First Sampling of the Oral Malodor Material-Containing Mouth Headspace

A sample of exhaled breath from the oral malodor material-treated oralcavity is tested to provide a test result representing an amount of atleast one oral malodor component detected in the exhaled breath.Optionally, the sample is taken at a period from 15 to 45 minutes afterthe commencement of the initial cleaning step.

The testing was carried out as described above for the sampling of thecleaned mouth headspace, i.e. a SPME fiber assembly 2 is used, and thenthe same gas chromatograph and mass spectrometry procedures are carriedout as described above. This sampling of the oral malodor materialcontaining mouth headspace provides a plurality of counts at arespective acquisition time for each component detected.

Again, the method of the invention may be used to detect only a singlecomponent. However, in other embodiments, plural components aredetected, each having a respective acquisition time, and the counts ateach acquisition time represents the amount of the respective componentpresent. In some embodiments, the testing step adds together the countsrepresenting the amounts of at least two or all of the detected oralmalodor components in the respective sample of exhaled breath to providea single quantified total count value for the sample of exhaled breath.The single quantified total count value represents oral malodorassociated with the oral malodor material in the oral malodormaterial-containing mouth headspace.

The test result may be compare with the baseline result to provide anindication of the ability of the oral care composition prophylacticallyto reduce oral malodor resulting from the oral malodor material.

Second Cleaning of the Mouth Headspace

In a further aspect, the method further provides an indication of theability of the oral care composition to refresh the oral cavity andreduce oral malodor resulting from previous exposure to the oral malodormaterial.

Thereafter, in order to determine the refresh-ability of the oral carecomposition, the method again cleans at least a part of the odoriferousoral cavity with the oral care composition to be tested.

The cleaning step again typically comprises brushing the teeth with theoral care composition, which is a toothpaste or dentifrice gel.Alternatively, the cleaning step may comprise rinsing the oral cavitywith the oral care composition, which is a mouthwash or mouthrinse. Thecleaning step preferably has a predetermined time period, and forexample may take from 30 seconds to 2 minutes, typically about 1 minute.Typically, the cleaning is carried out within a period of from 0 to 5minutes following the sampling of the second sample of exhaled breathfrom the oral malodor material-treated oral cavity using the fiberassembly 2.

Second Sampling of the Cleaned Oral Malodor Material-Containing MouthHeadspace

In a further testing step, a second sample of exhaled breath from theoral malodor material-treated and subsequently cleaned oral cavity istested to provide a second test result representing a second amount ofat least one oral malodor component detected in the exhaled breath.Optionally, the second sample is taken at a period from 30 to 60minutes, topically 40 minutes, after the commencement of the initialcleaning step.

The testing was carried out as described above for the sampling of thecleaned mouth headspace. A further SPME fiber assembly 2 is used, andthen the same gas chromatograph and mass spectrometry procedures arecarried out as described above. This sampling provides a plurality ofcounts at a respective acquisition time for each component detected.Again, the method of the invention may be used to detect only a singlecomponent. However, in the preferred embodiments, plural components aredetected, each having a respective acquisition time, and the counts ateach acquisition time represents the amount of the respective componentpresent. In some embodiments, the testing step adds together the countsrepresenting the amounts of at least two or all of the detected oralmalodor components in the respective sample of exhaled breath to providea single quantified total count value for the sample of exhaled breath.The single quantified total count value represents oral malodorassociated with the oral malodor material in the oral malodormaterial-containing and subsequently cleaned mouth headspace.

The second test result may be compared with the first test result toprovide an indication of the ability of the oral care composition torefresh the oral cavity and reduce oral malodor resulting from exposureto the oral malodor material.

The testing protocols described above may be used to compare theperformance of different oral care compositions in reducing oralmalodor, in particular onion and/or garlic malodor. For example, a firstoral care composition, formulated to provide oral malodor reduction, maybe used as a test sample, and a second oral care composition may be usedas a control sample.

The peaks in the chromatograms from the GC-MC readings can be convertedinto counts for the individual malodor component which can be identifiedby their individual acquisition times. The count data thus provides anumerical value for the detected amount of the respective malodorcomponent.

The invention also provides for a composition for testing the efficacyof an oral care composition to reduce oral malodor comprising at leastone compound selected from the group consisting of 3-methyl-furan,2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanol acetate,2-methylthio-methylfuran, 1-pentyl-pyrrole, 2,2′-methylbisfuran.

In another embodiment of the invention, the composition for testing theefficacy of an oral care composition to reduce oral malodor comprisingat least three compounds selected from the group consisting of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole,2,2′-methylbisfuran.

In another embodiment of the invention, the composition for testing theefficacy of an oral care composition to reduce oral malodor comprises3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole,2,2′-methylbisfuran.

In another embodiment of the invention, a composition for testing theefficacy of an oral care composition to reduce oral malodor describedabove have no additional ingredients.

The invention also provides for an oral composition detected by any ofthe above described methods, wherein the oral care composition is adentifrice, mouthwash, mouthrinse, toothpaste, gel, dental cream,chewing gum, or portable dosage article such as, without limitation, alozenge, a mint, bead, wafer, lollipop, liquid formulated for oralapplication in a small portable nebulizer (spray bottle), liquidformulated for oral application in a small portable drop-generatingbottle, or a soft pliable tablet which reduces oral malodor by at leastone compound selected from the group consisting of 3-methyl-furan,2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanol acetate,2-methylthio-methylfuran, 1-pentyl-pyrrole, and 2,2′-methylbisfuran andcomprises one or more of a carbonyl compound, a compound whichencapsulate the furan or pyrrole compounds, tetrasodium pyrophospate,flavorants and combinations thereof.

In another embodiment of the detected oral care composition, the oralcare composition reduces oral malodor at least three compounds selectedfrom the group consisting of 3-methyl-furan, 2,5-dimethyl-furan,2-furan-methanol, 2-furanmethanol acetate, 2-methylthio-methylfuran,1-pentyl-pyrrole, and 2,2′-methylbisfuran.

In another embodiment of the detected oral care composition, the oralcare composition reduces oral malodor from the combination of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.

The invention is illustrated in the following non-limiting examples.

EXAMPLES Example 1

An in vitro test method according to the invention was used to study theperformance of a toothpaste composition in reducing coffee oral malodor.

A toothpaste was tested using an embodiment of the method of theinvention to determine the ability (a) prophylactically to preventcoffee malodor in the mouth headspace by brushing before applying thecoffee malodor material, hereinafter called the stimulus, and (b) toremove coffee malodor in the mouth headspace by brushing after rinsingthe oral cavity with the stimulus.

Step 1—First Cleaning of the Mouth Headspace

The volunteer subject brushed their teeth with the respective toothpastefor a period of 1 minute.

Step 2 —Sampling of the Cleaned Mouth Headspace

The volunteer subject breathed through their mouth into a SPME (solidphase micro extraction) fiber assembly for a period of 1 minute so thata first sample of exhaled breath from the cleaned oral cavity was testedand the required oral malodor components were collected on the SPMEfibers. The fiber assembly was prevented from direct contact with themouth by a spacer tube of polymeric material. The fiber assemblycomprised fused silica fibers having a 75 micron coating ofCarboxen®/polydimethylsiloxane (CAR/PDMS) as the matrix active group,the fibre assembly having a black plain hub and being available fromSupelco, of Bellefonte, Pa., USA. The volunteer human subject breathedin through the nose and out through the mouth into the tube and fiberassembly.

The oral malodor components collected in the fiber assembly wereseparated using gas phase chromatography. The gas phase chromatographyemployed a gas chromatograph (GC) sold under the trade name GC7890A byAgilent Technologies, Palo Alto, Calif., USA. In the gas chromatographthe oven temperature was held at 35° C. for 1 minute, and then thetemperature was increased to 160° C. at a 15° C./min rate and held therefor another 2.667 minutes. The total running time was 12 minutes. Heliumwas used as the carrier gas and the flow rate was 1 mL/min. The injectortemperature was set up at 250° C. A SLBTM-5ms GC column (30 m×0.25mm×0.25 μm film thickness, available from Sigma-Aldrich, Bellefonte,Pa.) was used for the separation of the oral malodor componentscollected in the fiber assembly.

After the oral malodor components collected in the fiber assembly hadbeen separated, an amount of the separated oral malodor components wasdetermined using mass spectrometry to provide a quantificationrepresenting an amount of the oral malodor components in the sample ofexhaled breath.

The mass spectrometer comprised a 7000MS Triple Quadrupole MassSpectrometer available from Agilent Technologies, Palo Alto, Calif.,USA. The non-ionization for solvent delay was from 0 to 0.5 minutes. Themass spectrometry detection was switched on at 0.5 minutes.

The mass spectrometer recorded a plurality of counts at a respectiveacquisition time for each component detected. Seven oral malodorcomponents were detected, each having a respective acquisition time, andthe counts at each acquisition time represented the amount of therespective component present.

In this Example, for detecting onion malodor, the oral malodorcomponents detected were 3-methyl-furan, 2,5-dimethyl-furan,2-furan-methanol, 2-furanmethanol acetate, 2-methylthio-methylfuran,1-pentyl-pyrrole, 2,2′-methylbisfuran.

When these particular oral malodor components were detected, theacquisition times were as follows using the 7000MS Triple QuadrupoleMass Spectrometer and the parameter settings as set out above.

From 0.5 to 2.8 minutes, 2-methyl-furan may be detected with a molecularion at 82.8 and daughter ion at 53.0 and the collision energy was 20 eV.From 2.8 to 4 5 minutes, 2,5-dimethylfuran may be detected with amolecular ion at 96.2 m/z and daughter ion at 81.0 m/z and the collisionenergy was 10 eV. From 4.5 to 5.5 minutes, 2-furanmethanol may bedetected with a molecular ion at 98.2 m/z and daughter ion at 42.1 m/zand the collision energy was 10 eV. From 6.0 to 6.23 minutes,2-furanmethanol acetate may be detected with a molecular ion at 140.2m/z and daughter ion at 98.2 m/z and the collision energy was 10 eV.From 6.23 to 6.70 minutes, 2-methylthio methylfuran may be detected witha molecular ion at 128.2 m/z and daughter ion at 80.9 m/z and thecollision energy was 10 eV. From 6.7 to 7.1 minutes, 1-penyl-pyrrole maybe detected with a molecular ion at 137.2 m/z and daughter ion at 80.9m/z and the collision energy was 10 eV. From 7.1 to 12 0 minutes,2,2′-methyl-bisfuran may be detected with a molecular ion at 148.2 m/zand daughter ion at 91.2 m/z and the collision energy was 10 eV. Thecount total of each component was recorded to indicate the amount ofthat component which had been detected.

Step 3—Introducing Oral Malodor Material into the Mouth

Thereafter, the oral cavity of the volunteer subject was exposed tomeasured dose of coffee malodor material. The exposure to oral malodormaterial was carried out about 15 to 20 minutes after the commencementof the initial cleaning of the oral cavity.

To prepare a measured dose of coffee malodor material, concentration ofcoffee from 2 mg/mL to 16 mg/mL was prepared. The coffee odor wasintroduced into the oral cavity by rinsing the mouth with 3 mL of thatcoffee malodor solution for 1 minute.

Step 4—First Sampling of the Malodorous Mouth Headspace

In a further testing step, a first sample of exhaled breath from theoral malodor material-treated oral cavity was tested to provide a firsttest result representing a first amount of at least one oral malodorcomponent detected in the exhaled breath. The first sample was taken ata period of 20 minutes after the commencement of the initial cleaningstep.

The testing was carried out as described above for the sampling of thecleaned mouth headspace. A further SPME fiber assembly 2 was used, andthen the same gas chromatograph and mass spectrometry procedures werecarried out as described above. This sampling provided a plurality ofcounts at a respective acquisition time for each component detected.Again, the method of the invention was used to detect the seven oralmalodor components as in the previous sampling.

Step 5—Second Cleaning of the Mouth Headspace

Further testing was conducted to provide an indication of the ability ofthe oral care composition to refresh the oral cavity and reduce oralmalodor resulting from previous exposure to the oral malodor material.

The oral care composition to be tested was used again to clean the oralcavity. The cleaning step again comprised brushing the teeth with thetoothpaste for a time period of 1 minute. The cleaning was carried outwithin a period of from 0 to 5 minutes following the sampling of thefirst sample of exhaled breath from the oral malodor material-treatedoral cavity.

Step 6—Second Sampling of the Malodorous then Cleaned Mouth Headspace

In a further testing step, similar to the first sampling tests, a secondsample of exhaled breath from the oral malodor material-treated andsubsequently cleaned oral cavity was tested to provide a second testresult representing a second amount of the seven oral malodor componentsdetected in the exhaled breath. The second sample was taken at a periodof 40 minutes after the commencement of the initial cleaning step.

The testing was carried out as described above for the previoussamplings. A further SPME fiber assembly was used, and then the same gaschromatograph and mass spectrometry procedures were carried out asdescribed above. This sampling provided a plurality of counts at arespective acquisition time for each component detected. Again, themethod of the invention was used to detect the seven oral malodorcomponents as in the previous sampling.

Step 7—Comparison of Results of First and Second Samplings

The data from the chromatograms of the first and second samplings wasanalysed by comparing, for each of the seven detected oral malodorcomponents, a quantification of the count values of the first and secondsamplings.

To determine the ability of the tested oral care compositionprophylactically to prevent onion malodor in the mouth headspace, foreach of the seven detected oral malodor components, the first and secondcount values are compared.

To determine the ability of the tested oral care composition to removeonion malodor already existing in the mouth headspace, for each of theseven detected oral malodor components, the first and second countvalues are compared.

By comparing the results for one oral care composition against anotheroral care composition, the efficacy of each oral care compositionagainst oral malodor can be quantified using a robust and repeatabletest. The efficacy for malodor removal can be expressed as a percentagereduction in the count value for a more effective composition ascompared to a less effective composition.

Of course, other data analysis techniques may be employed to analyse thecount data to provide an indication of the efficacy, absolute orcomparative, of the tested oral care composition(s).

For each of the first and second samplings, the counts representing theamounts of all seven of the detected oral malodor components in therespective sample of exhaled breath were added together to provide asingle quantified total count value for the sample of exhaled breath.The single quantified total count value represents oral malodorassociated with the oral malodor material in the respective sampling.

Again, by comparing the single quantified total count values for oneoral care composition against another oral care composition, theefficacy of each oral care composition against oral malodor can bequantified using a robust and repeatable test.

Example 2

An in vitro test method according to the invention was used to study theperformance of different toothpaste compositions in reducing coffee oralmalodor.

A control toothpaste and a test toothpaste containing an coffee malodoragent were measured on a volunteer using an embodiment of the method ofthe invention to determine their respective ability (a) prophylacticallyto prevent coffee malodor in the mouth headspace by brushing beforeapplying the stimulus, and (b) to remove coffee malodor in the mouthheadspace by brushing after rinsing the oral cavity with the stimulus.The same sequence of steps as described above for Example 1 was used. Ineach sequence, the control toothpaste and the test toothpaste weretested independently.

The same coffee malodor material was used. All seven oral malodorcomponents were determined in each of the three samplings. Compound 1was 3-methyl furan, compound 2 was 2,5-dimethyl-furan, compound 3 was2-furan-methanol, compound 4 was 2-furanmethanol acetate, compound 5 was2-methylthio-methylfuran, compound 6 was 1-pentyl-pyrrole, and compound7 was 2,2′-methylbisfuran.

The results for the malodor prophylactic test, analysing the count datafrom the first (after 20 minutes) are shown in Tables 1-4.

-   -   Key to Tables 1-4:    -   A (malodor compound number—(1) 3-methyl-furan, (2)        2,5-dimethyl-furan, (3) 2-furan-methanol, (4) 2-furanmethanol        acetate, (5) 2-methylthio-methylfuran, (6) 1-pentyl-pyrrole, (7)        2,2′-methylbisfuran.    -   Control toothpase—contains tetrasodium pyrophosphate (TSPP) and        flavor    -   B (Control toothpaste—Malodor count from triple quad MS        detector)    -   C (Control toothpaste+1% composition containing carbonyl        compounds—Malodor count from triple quad MS detector).    -   D (% Malodor compound reduction—comparison of B vs. C)

TABLE 1 RT A B C D 1.7 (1) 7523 4194 44.3% 3.3 (2) 5450 5101 6.4% 5.2(3) 30154 20974 30.4% 5.6 (4) 111 121 [9.1%] 6 (5) 2047 2631 [28.5%] 7.5(6) 223 230 [3.1%] 8.1 (7) 1027 1157 [12.7%] Total 46535 34408 26.1%

TABLE 2 RT A B C D 1.7 (1) 45462 17109 62.4% 3.3 (2) 15568 6958 55.3%5.2 (3) 64183 37873 41.0% 5.6 (4) 554 186 66.4% 6 (5) 6664 3978 40.3%7.5 (6) 936 596 36.3% 8.1 (7) 7006 3539 49.5% Total 140373 70239 50.0%

TABLE 3 RT A B C D 1.7 (1) 8360 11600 [38.8%] 3.3 (2) 8354 7176 14.1 5.2(3) 121201 97877 19.2 5.6 (4) 3283 2184 33.5 6 (5) 3565 4067 [14.1%] 7.5(6) 471 472 [0.02%] 8.1 (7) 4361 3959  9.2% Total 149595 127335 14.9%

The above data shows that the SPME—GC/MS method of the invention allowsfor rapid determination that the toothpaste with a carbonyl compoundprovided lower counts overall for the individual malodor compounds andcompared with the same toothpaste without a carbonyl compound and wasable to provide this data for the seven malodor compounds with only onetest sample. This provided a quantified indication of the prophylacticefficacy and ability to reduce malodor components by the test toothpasteagainst oral malodor.

By detecting the all of the major components of malodor by theSPME—GC/MS method of the invention, it was confirmed that the reductionin malodor came from an actual decrease in the amount of malodorcompounds and was not the result of masking, i.e. the present of acarbonyl compound improved malodor removal better than a comparabletoothpaste with TSPP and flavor.

The presently claimed method provides a means for selecting the properdentifrice for providing a prophylactic effect for treating malodor andalso for selecting the proper dentifrice for providing a reduction inmalodor components.

By having this rapid access to data related to malodor treatment, notonly can improved malodor compositions be developed, but suchcompositions can either be selected over other less effectivecompositions and facilitate the tailoring of compositions to anindividual's needs by incorporating different or additional agents toreduce malodor compounds (e.g. compound (6) was reduced only withpanellist 2 (Table 2—40.3%) whereas panellists 1 and 3 saw increases incompound (6)).

While particular embodiments of the invention have been illustrated anddescribed, it will be obvious to those skilled in the art that variouschanges and modifications may be made without departing from the scopeof the invention as defined in the appended claims.

1. A method for testing the efficacy of and selecting an oral carecomposition to reduce oral malodor, wherein the method comprises thesteps of: a1. cleaning at least a part of the oral cavity with an oralcare composition and testing the cleaned oral cavity to provide abaseline amount of at least one oral malodor component detected in theexhaled breath; b1. exposing the oral cavity to an oral malodor materialcontaining the at least one oral malodor component; c1. obtaining asample of exhaled breath from the oral cavity to detect a amount of theat least one oral malodor component in the exhaled breath which is arepresentation of the propylactic effect of the oral care composition;and d1. comparing the amount of the at least one oral malodor componentdetected in the exhaled breath after cleansing with an oral carecomposition with a amount from cleansing with a different oral carecomposition and selecting the oral care composition with the loweramount for a method of providing prophylactic effect against at leastone malodor component in the oral cavity.
 2. A method for testing theefficacy of and selecting an oral care composition to reduce oralmalodor, wherein the method comprises the steps of: e1. exposing theoral cavity to an oral malodor material containing the at least one oralmalodor component; f1. cleaning at least a part of the oral cavity withthe oral care composition; g1. obtaining a sample of exhaled breath fromthe oral cavity to detect an amount of the at least one oral malodorcomponent in the exhaled breath which is a representation of theefficacy of the oral care composition to reduce oral malodor; and h1.comparing the amount of the at least one oral malodor component detectedin the exhaled breath after cleansing with an oral care composition instep e1 with a amount from cleansing with a different oral carecomposition and selecting the oral care composition with the loweramount for a method of reducing at least one malodor component in theoral cavity.
 3. A method for testing the efficacy of and selecting anoral care composition to reduce oral malodor, the method comprising oneor more of the steps of: a2. cleaning at least a part of the oral cavitywith an oral care composition and testing the cleaned oral cavity toprovide a baseline amount of at least one oral malodor componentdetected in the exhaled breath; b2. exposing the oral cavity to an oralmalodor material containing the at least one oral malodor component; c2.obtaining a sample of exhaled breath from the oral cavity to detect aamount of the at least one oral malodor component in the exhaled breathwhich is a representation of the propylactic effect of the oral carecomposition; d2. optionally, comparing the amount of the at least oneoral malodor component detected in the exhaled breath after cleansingwith an oral care composition with an amount from cleansing with adifferent oral care composition and selecting the oral care compositionwith the lower amount for a method of providing prophylactic effectagainst at least one malodor component in the oral cavity; e2. cleaningat least a part of the oral cavity with the oral care composition fromstep a2; f2. obtaining a sample of exhaled breath from the oral cavityto detect an amount of the at least one oral malodor component in theexhaled breath which is a representation of the efficacy of the oralcare composition to reduce oral malodor; and g2. optionally, comparingthe amount of the at least one oral malodor component detected in theexhaled breath after cleansing with an oral care composition in step e2with an amount from cleansing with a different oral care composition andselecting the oral care composition with the lower amount for a methodof reducing at least one malodor component in the oral cavity.
 4. Themethod of any of the foregoing claims, wherein the oral malodor materialis from coffee.
 5. The method of any of the foregoing claims, whereinthe cleaning step comprises: (i) brushing the teeth with the oral carecomposition which is a toothpaste or dentifrice gel and/or (ii) rinsingthe oral cavity with the oral care composition which is a mouthwash ormouthrinse.
 6. The method of any one of the foregoing claims, whereinthe malodor component is a furan or pyrrole compound.
 7. The method ofany one of the foregoing claims, wherein the malodor component is atleast one oral malodor component selected from the group consisting of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.
 8. The method of any one of the foregoing claims,wherein the the malodor component is at least three oral malodorcomponents selected from the group consisting of 3-methyl-furan,2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanol acetate,2-methylthio-methylfuran, 1-pentyl-pyrrole, and 2,2′-methylbisfuran. 9.The method of any one of the foregoing claims, wherein the oral malodorcomponent is the combination of 3-methyl-furan, 2,5-dimethyl-furan,2-furan-methanol, 2-furanmethanol acetate, 2-methylthio-methylfuran,1-pentyl-pyrrole, and 2,2′-methylbisfuran.
 10. The method of any one ofthe foregoing claims, wherein the oral composition contains one of morecompound selected from the group consisting of a carbonyl compound, acompound which encapsulates a sulfide compound, tetrsodiumpyrophosphate, a flavorant and combinations thereof.
 11. The method ofany one of the foregoing claims, wherein each obtaining step includesthe sub-steps of: i. collecting the at least one oral malodor componenton solid phase micro extraction (SPME) fibers; ii. separating thecollected at least one oral malodor component using chromatography; andiii. determining an amount of the separated at least one oral malodorcomponent using mass spectrometry to provide a quantificationrepresenting an amount of the at least one oral malodor component in therespective sample of exhaled breath.
 12. The method of any one of theforegoing claims, wherein the chromatography is gas phase chromatography(GC) and/or the mass spectrometry (MS) is triple quadrupole massspectrometry.
 13. The method of any one of the foregoing claims, whereinstep b1 or b2 is carried out from 10 to 30 minutes after step a1 or a2,respectively, step c1 or c2 is carried out from 15 to 45 minutes afterstep a1 or a2, respectively, and step e1 or e2 is carried out from 30 to60 minutes after step a1 or a2, respectively.
 14. The method of claim 3,wherein the method comprising the steps of: a2. cleaning at least a partof the oral cavity with an oral care composition and testing the cleanedoral cavity to provide a baseline amount of at least one oral malodorcomponent detected in the exhaled breath; b2. exposing the oral cavityto an oral malodor material containing the at least one oral malodorcomponent; c2. obtaining a sample of exhaled breath from the oral cavityto detect a amount of the at least one oral malodor component in theexhaled breath which is a representation of the propylactic effect ofthe oral care composition; d2. comparing the amount of the at least oneoral malodor component detected in the exhaled breath after cleansingwith an oral care composition with a amount from cleansing with adifferent oral care composition and selecting the oral care compositionwith the lower amount for a method of providing prophylactic effectagainst at least one malodor component in the oral cavity; e2. cleaningat least a part of the oral cavity with the oral care composition fromstep a2; f2. obtaining a sample of exhaled breath from the oral cavityto detect an amount of the at least one oral malodor component in theexhaled breath which is a representation of the efficacy of the oralcare composition to reduce oral malodor; and g2. comparing the amount ofthe at least one oral malodor component detected in the exhaled breathafter cleansing with an oral care composition in step e2 with an amountfrom cleansing with a different oral care composition and selecting theoral care composition with the lower amount for a method of reducing atleast one malodor component in the oral cavity.
 15. The method of any ofthe foregoing claims wherein, the oral composition selected in step d1or d2 is different than the original oral composition selected in stepa1 or a2.
 16. The method of of any of the foregoing claims wherein, theoral composition selected in step g1 or g2 is different than theoriginal oral composition selected in step a1 or a2.
 17. A compositionfor testing the efficacy of an oral care composition to reduce oralmalodor comprising at least one compound selected from the groupconsisting of 3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol,2-furanmethanol acetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.
 18. The composition of claim 17, which comprises atleast three compounds selected from the group consisting of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.
 19. The composition of claim 18, which comprisesthe combination of 3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol,2-furanmethanol acetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.
 20. The composition of any of claims 17-19, whereinthere are no additional ingredients.
 21. An oral care compositiondetected by any of the methods of claims 1-16, wherein the oral carecomposition is a dentifrice, mouthwash, mouthrinse, toothpaste, gel,dental cream, chewing gum, or portable dosage article such as, withoutlimitation, a lozenge, a mint, bead, wafer, lollipop, liquid formulatedfor oral application in a small portable nebulizer (spray bottle),liquid formulated for oral application in a small portabledrop-generating bottle, or a soft pliable tablet which reduces oralmalodor by at least one compound selected from the group consisting of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran and comprises one or more of a carbonyl compound, acompound which encapsulate the furan or pyrrole compounds, tetrasodiumpyrophospate, flavorants and combinations thereof.
 22. The oral carecomposition of claim 21, wherein the oral care composition reduces oralmalodor at least three compounds selected from the group consisting of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.
 23. The oral care composition of claim 22, whereinthe oral care composition reduces oral malodor from the combination of3-methyl-furan, 2,5-dimethyl-furan, 2-furan-methanol, 2-furanmethanolacetate, 2-methylthio-methylfuran, 1-pentyl-pyrrole, and2,2′-methylbisfuran.